Relative Bioavailabilities of Natural and Synthetic Vitamin E Formulations Containing Mixed Tocopherols in Human Subjects

1999 ◽  
Vol 69 (2) ◽  
pp. 92-95 ◽  
Author(s):  
Chopra ◽  
Bhagavan

There are several reports in the literature on the relative bioavailabilities of RRR (natural) vs. all-rac (synthetic) forms of vitamin E in humans and animal models but none on the bioavailability of alpha-tocopherol in mixed vitamin E formulations. In the present study we examined the bioavailability of alpha-tocopherol in a typical commercially available product containing mixed tocopherols. We also tested a formulation containing all-rac-alpha-tocopherol with mixed tocopherols for purposes of comparison along with straight RRR-and all-rac-alpha-tocopheryl acetate as reference products. Normal male subjects were given one of the four formulations of vitamin E (800 IU per day in softgel capsule form for 10 days): 1. All-rac-alpha-tocopheryl acetate, 2. RRR-alpha-tocopheryl acetate, 3. RRR-alpha-tocopherol with mixed tocopherols, and 4. all-rac-alpha-tocopherol with mixed tocopherols. Both serum alpha- and gamma-tocopherols were determined by HPLC at baseline, and at days 2, 4, 7 and 10. The values for alpha- at baseline and 10 days were 0.80, 0.80, 0.80 & 0.79 mg/dl and 1.67, 1.72, 1.76 & 1.62 mg/dl. The values for gamma- were 0.28, 0.29, 0.30 & 0.29 mg/dl and 0.11, 0.08, 0.10 & 0.10 mg/dl. Thus the data show that a) the bioavailability of RRR-and all-rac-alpha-tocopherols is not affected by other tocopherols, and b) both RRR-and all-rac-alpha-tocopherol (free or esterified) significantly suppress the serum gamma tocopherol to the same extent. Furthermore, since there was no difference in the serum values of alpha-tocopherol between RRR-and all-rac-vitamin E given the same dose as IUs, the data also support the currently accepted ratio of 1.36 for the biopotency of RRR- vs. all-rac-alpha-tocopheryl acetate.

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1795-1795
Author(s):  
Chen Du ◽  
Gina Tran ◽  
Victorine Imrhan ◽  
Chandan Prasad ◽  
Parakat Vijayagopal ◽  
...  

Abstract Objectives The purpose of this study was to compare the effects of alpha tocopherol, gamma tocopherol, and the combination of alpha and gamma tocopherols on bone mineral density (BMD), bone mineral content (BMC), and bone metabolism in C57BL/6 J mice fed a high-fat diet. Methods A total of 75 male C57BL/6 mice were randomized to either a low fat diet (LFD) with 6% fat, a high fat diet (HFD) with 20% fat, HFD supplemented with alpha tocopherol (AT), gamma tocopherol (GT), or the combination of AT and GT. LFD and HFD were provided to corresponding groups of mice without vitamin E isoform supplements for 15 weeks to induce bone loss. At the end of the 15 weeks, AT, GT, and a combination of AT and GT were added to 3 of the HFD groups and fed for 10 weeks. LFD group and one of the HFD groups were continued on the same diet for another 10 weeks without additional supplements. All mice were euthanized at the end of the 25 weeks period. Left and right fibula bones were excised, cleaned, and scanned using the Lunar PIXImus dual-energy x-ray absorptiometry (DEXA) densitometer to assess BMD, BMC, lean tissue, and fat tissue content. Serum biomarkers of bone metabolism were evaluated post euthanization. Results HFD resulted in significantly lower fibular BMD and higher tibial bone fat content in comparison to LFD. Animals in the HFD supplemented with GT, but not AT, showed significantly reduced effect of HFD in lowering BMD. Additionally, in the group fed HFD supplemented with GT, a significantly higher concentration of alkaline phosphatase (ALP) and N-terminal propeptide of type I procollagen (PINP) were noted, compared to LFD. This may be indicative of increased bone formation resulting from GT incorporated into the HFD diet. Conclusions The findings of the study suggest that different isoforms of vitamin E affect bone density and bone metabolism differently. Within the different isoforms of vitamin E, gamma tocopherol may have protective effects in bone, especially in the situation of high fat diet induced bone loss. Further examination of the mechanistic action of vitamin E isoforms on skeletal health is warranted. Funding Sources Texas Woman's University.


1991 ◽  
Vol 82 (5) ◽  
pp. 511-517 ◽  
Author(s):  
Yumiko Nitta ◽  
Kenji Kamiya ◽  
Masanori Tanimoto ◽  
Seiji Sadamoto ◽  
Ohtsura Niwa ◽  
...  

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3793-3793
Author(s):  
Omar S. Aljitawi ◽  
Mathew Fitzgerald ◽  
Min Qui ◽  
Koyamangalath Krishnan ◽  
William L. Stone ◽  
...  

Abstract Vitamin E, the main lipid soluble antioxidant, exists in eight different forms, of which α-tocopherol and γ-tocopherol are the two major forms. Previous experiments showed vitamin E uptake by macrophages that contribute to inflammation and immunity. On the other hand, vitamin E has structural similarity to the thiazolidinedione, troglitazone, a peroxisome proliferator-activated receptor (PPAR) agonist. In previous experiments we found that troglitazone (TGZ), a PPAR gamma agonist, had a negative effect on mast cell cytokine production. We therefore wondered whether vitamin E enters human mast cells, and if so, does this modulate mast cell cytokine production? We choose (interleukin) IL-6 for its pro-inflammatory properties and because it’s known to be produced by mast cells in response to stimulants used in the experiment. In this study we try to answer these two questions. Cultured human mast cell line (HMC-1) was first incubated for 24 hrs with pharmacological concentrations of both alpha and gamma forms of vitamin E (10 μM). The mast cells were then activated with phorbol-12-myristate-13-acetate [PMA (50ng/ml)] and ionomycin (5μm) for 24 hours and cell-free supernatants collected. In additional experiments, IL-1ß (10ng/mL) was added to activate mast cells. IL-6 levels in the supernatants were determined in each well utilizing ELISA. Mast cell concentrations of alpha or gamma tocopherol were measured by high pressure liquid chromatography [HPLC] and electrochemical analysis. Mast cells pre-incubated in alpha and gamma forms of vitamin E at 10 μM did not affect mast cell IL-6 production. Mast cells, however, showed uptake of both forms of tocopherols but more pronounced uptake of the gamma form (13181.05 pmole/well of gamma compared to 8742.99 pmole/well of alpha tocopherol). We conclude that mast cells appear to store both alpha and gamma tocopherols but preferentially more gamma tocopherol. Though Vitamin E and PPAR agonists have similar structures, they did not show similar effect on mast cell cytokine production, suggesting they might have different mechanisms of action.


2008 ◽  
Vol 52 (4) ◽  
pp. 447-456 ◽  
Author(s):  
Weiping Yu ◽  
Li Jia ◽  
Pei Wang ◽  
Karla A. Lawson ◽  
Marla Simmons-Menchaca ◽  
...  

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Alison M. Mondul ◽  
Steven C. Moore ◽  
Stephanie J. Weinstein ◽  
Anne M. Evans ◽  
Edward D. Karoly ◽  
...  

Background. The Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study, a randomized controlled cancer prevention trial, showed a 32% reduction in prostate cancer incidence in response to vitamin E supplementation. Two other trials were not confirmatory, however.Objective. We compared the change in serum metabolome of the ATBC Study participants randomized to receive vitamin E to those who were not by randomly selecting 50 men from each of the intervention groups (50 mg/day all-rac-α-tocopheryl acetate (ATA), 20 mg/dayβ-carotene, both, placebo).Methods. Metabolomic profiling was conducted on baseline and follow-up fasting serum (Metabolon, Inc.).Results. After correction for multiple comparisons, five metabolites were statistically significantly altered (βis the change in metabolite level expressed as number of standard deviations on the log scale):α-CEHC sulfate (β=1.51,p=1.45×10-38),α-CEHC glucuronide (β=1.41,p=1.02×10-31),α-tocopherol (β=0.97,p=2.22×10-13),γ-tocopherol (β=-0.90,p=1.76×10-11), andβ-tocopherol (β=-0.73,p=9.40×10-8). Glutarylcarnitine, beta-alanine, ornithine, and N6-acetyllysine were also decreased by ATA supplementation (βrange 0.40 to −0.36), but not statistically significantly.Conclusions. Comparison of the observed metabolite alterations resulting from ATA supplementation to those in other vitamin E trials of different populations, dosages, or formulations may shed light on the apparently discordant vitamin E-prostate cancer risk findings.


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